This invention relates to stage lighting and is particularly concerned with the control of multiple functions of a lamp.
It has already been proposed to incorporate in a lamp unit a plurality of different functions, such as colour changers, focusing lenses, iris diaphragms, gobo selectors and pan and tilt mechanisms which are controlled from a remote console. Stage lighting systems have as a result reached very high levels of complexity requiring a very complicated main control console and lamp unit constructions. The use of microprocessors, both in the console and the lamps has become conventional as increasing complexity makes it more difficult to produce and subsequently maintain a system which uses hard wired logic or analog controls. In such systems the microprocessor in the console is used to allow the user to set up lighting cues and to control the sending of appropriate data to the lamp microprocessors. The lamp microprocessors are also involved in controlling communication between the console and the lamps, and also have to control a plurality of servomotors which drive the various functions of the lamps.
It is one object of the present invention to provide a lamp microprocessor and servo-control arrangement which allows complex functions to be carried out.
It is another object of the invention to provide a lamp control system in which control of pan and tilt movements of each lamp can be carried out in rapid and efficient manner, enabling large groups of lamps to make co-ordinated movements.
It is yet another object of the invention to provide each lamp in a stage lighting system with a means for quickly interrupting its light beam and quickly re-establishing the beam so that a group of lamps can be made, when required to flash in synchronism.
In accordance with one aspect of the invention there is provided a lamp unit for connection to a remote control console for the control of a plurality of different functions of the lamp, said unit comprising a main processor circuit, associated with a communication controller for accepting message data from the console, a plurality of servo-controls for operating said functions of the lamp, and a plurality of co-processors which are connected to the main processor circuit so as to be supplied thereby with desired value data for the various lamp functions, said servo-controls being controlled by said co-processors.
In the case of pan and tilt controls where close control is required throughout the movement of the lamp from an initial position to a new position, one of the co-processors is assigned solely to the control of movement about each axis. Other functions can share a co-processor.
The main processor circuit of the lamp is preferably programmed to accept data from the control console defining not only a target position for any function, but also a duration over which the function is to be executed. In this case the main processor circuit divides the xe2x80x9cjourneyxe2x80x9d into segments and updates the target position data passed to the associated co-processor at intervals.
In accordance with another aspect of the invention, there is provided a lighting control apparatus comprising the combination of a main control console for accepting user input relating to required beam movements, a plurality of independently operable lamp units situated remotely from the console, each of the lamp units incorporating a servomechanism for automatically moving the lamp beam about two mutually transverse axes to a desired angular position and data communication means connecting the console to the lamp units for the transmission of desired position data to the lamp units, the desired position data being transmitted in the form of a set of three dimensional linear co-ordinates defining a point in space through which the lamp beam is required to pass, and each lamp unit including a calculating device for calculating the desired angular position from the desired position data and supplying the servo-mechanism with such desired angular position.
In addition to the xe2x80x9cpoint atxe2x80x9d mode of operation mentioned above, additional modes may be specified in which the lamps point away from the specified point or in which they all point in the same direction parallel to a line between a fixed position in the co-ordinate system and the specified point.
Conveniently, all the data concerning the positions and orientations of the individual lamp units within the co-ordinate system is stored in a set-up file kept on a hard disk drive in the console. When the same lighting set-up is used at different venues, where it is impossible to set the frame which carries all the lamp units at exactly the same position as that for which the set-up was designed, offset data can be input at the console and either used within the console microcomputer to correct the position data stored during set-up as it is sent out, or such data can be sent to all or the lamp units over the network and stored there, to enable the corrections to be made in the individual lamp processor units.
In accordance with another aspect of the invention, a stage lighting unit comprises a housing, a light source within said housing, an optical system for forming light from said light source into a beam, a rotary shutter device having a plurality of blades, said shutter device being rotatably mounted in the housing so as to cause said blades to pass through and obstruct said beam as the shutter device rotates, a motor for rotating said shutter device and a servo-control for controlling said motor in accordance with data received in use from a remote control console.
The invention also resides in a stage lighting system incorporating a plurality of lighting units as defined above controlled by a common remote control console via data communication means, whereby the rotary shutter devices of all the units can operate in synchronism.